Carburetor



July 23, 1935. F. STOKES 2,008,804

CARBI'JRETOR Filed Nov. 27, 1951 2 Sheets-Sheet 1 gwoem com flva nz saw M ZL F. STOKES CARBURETOR July 23, 1935. 0

Filed Nov. 27, 1951 2 Sheets-Sheet 2 Patented July 23, 1935 PATENT OFFICE.

2,008,804 CARBURVETOR Fremont Stokes, Clarksville, 'Ark.; w. E. Johnston administrator of said Fremont Stokes,

deceased Application November 27, 1931, Serial No. 577,607

13 Claims. (01. 26178) This invention relates to carburetors and it has particular relation to a novel and extremely engine.

Most carburetors used today in connection with automobile engines and the like are of complicated construction and are inoperative unless associated with a vacuum tank or a fuel feed pump.

The primary object of this invention is ,to provide a carburetor of unusually simple construction which obviates the necessity of using either a vacuum tank or a fuel pump.

A further object of my invention is to provide a simple and eflicient carbureting device characterized by a novel fuel and air mixing nozzle and air controlling means which constitute its sole essential operative parts.

A still further object of this invention is to provide an extremely efiicient carburetor which effects great economies in fuel consumption by thorough atomization or vaporization of the fuel and complete integration thereof with air to form ahighly combustible fuel charge.

, A further object of this invention is to provide a direct feed for fuel between a supply tank and an internal combustion engine, and in connection therewith to provide a novel charge forming device operative to take fuel directly from the tank, integrate the same with air to form a combustible charge and deliver the same to the engine as may be required under varying conditions of engine speed and load.

1 Another object of this invention is to provide a carburetor which, in its simplest form, involves a minimum of moving parts and therefore will not become out of order through use and require repair.

For a better understanding of the invention reference may be had to the accompanying drawings forming a part of the disclosure, wherein:

Fig. 1 is a side elevational view of a preferred embodiment of the invention, partly broken away to disclose normally hidden parts,

Fig. 2 is a sectional view taken substantially on the line 2-2 of Fig. 1,

Fig. 3 is a central vertical sectional view of the structure taken on the line 3-3 of Fig. 2, illustrating the nozzle and by-pass constructions in greater detail,

,Fig. 4 is a detail sectional view taken on the line 4-4 of Fig. 1, illustrating a form of fuel feed control valve which may be utilized, and

Fig. 5 isa detail sectional view taken substantially on the line 5-5 of Fig. 1. I

Fig. 6 is a view more or less diagrammatic, showing a direct feed for fuelfrom a supply tank to an engine, and with the device of Fig. 1 inter- 5 posed therein to perform the dual function of fuel supplying and fuel carbureting.

In order that the functioning of my invention may be clearly understood, brief consideration will first be given to the principles which control its 0 operation. Substantially all carbureting devices for internalcombustion engines are independent in their operation upon the vacuum, or evacuated condition, produced in the intake manifold of the engine as a means of carbureting the fuel and supplying the same to the engine cylinders. The ordinary carburetor is provided with a fuel reservoir to which fuel is supplied from the supply tank by means of a fuelpump or vacuum tank. By the use of suitable instrumentalities the fuel is vaporized in the carburetor, such as by passing the same through a small aperture under natural air pressure in accordance with the vacuum present in the engine manifold. Despite the changes and improvements in devices of such general character which have been made over a period of many years, it must be conceded that such devices are relatively inefficient in operation in that they fail to properly integrate the fuel and air with result that the fuel charge produced is not of as highly combustiblecharacter as it should be, in View of the potentialities of the fuel.

The present invention, like prior devices of the same general character, operates in accordance with the difference in pressureexisting in the atmosphere and in the intake manifold of the engine, but such is to be differentiated from known devices in that suchdifference in pressure is utilized in a novel manner to produce the desired carburetion of the fuel. According to the proposed arrangement a portion of the air supply is admitted into a carburetor through suitable passages of small size under tremendous velocity to satisfy the evacuated condition produced by the engine. A small chamber connecting with a source of fuel is disposed in the carburetor adjacent to the air passages so that as the air passes into the carburetor the chamber will be evacuated, thus causing fuel from the source of supply to be forced into the same under natural air pressure existing at the source of fuel and thence pass outwardly to meet the high velocity air streams and thereby be thoroughly vaporized. To put the matter in otherwords, the

vacuum existing in the intake manifold of the engine causes an evacuated condition in the carburetor, which in turn causes air under a high velocity to rush therein. The incoming air causes an evacuated condition in the fuel chamber located in the carburetor, which in turn causes fuel under natural pressure from a. source to be supplied thereto. The fuel is in turn brought into contact with the air, by which it is atomized. It will thus be understood that the principles of operation of the present device are materially different from those of carburetors of known type.

In View of what has just been stated, it will be appreciated that the present device operates to draw fuel from any source, and, therefore, does not require the use in connection therewith of a fuel pump or a vacuum tank. While such devices are not necessary to successful operation,

they may be used if so desired. The same may be said with reference to the use of a float chamber, or'reservoir, as a part of a carburetor.

By reason of its ability to obtain fuel from a source independent of any mechanical expedients or the force of gravity, my invention may be directly connected to a fuel tank, receive fuel therefrom under the differential pressure between the source and the intake manifold of an engine according to the principles of operation heretofore described, and thoroughly atomize the fuel so as to produce a highly explosive fuel charge for the engine.

Referring now to the drawings, I have in Figs. 1-5 illustrated one embodiment of my inven tion which broadly considered, comprises a housing, or main mixing chamber formed for attachment tothe intake manifold of an internal combustion engine andprovided with a main air intake. Extending into the housing is a small chamber, or dome, connecting with a source of fuel supply and located adjacent thereto is a series of air ports of small size through'which air passes into the housing. The fuel chamber is closed with the exception of a series of small openings at the lower end thereof adjacent and extending preferably at right angles to the air ports, such arrangement being calculated to cause the air passing in through the ports to evacuate the chamber, thus causing the same to be filled with fuel from the supply. The fuel from said chamber thereupon passes outward from the openings where it meets the air rushing into the housing and is shattered thereby into small particles. A common type of butterfly valve is used to control the passage of the carbureted fuel mixture through the housing and a choke valve operating in unison therewith, controls the admission of air through the main air inlet. The two valves are manually controlled by the operator in the usual manner, and the main butterfly valve is capable of completely shutting off the passage through the housing. A by-pass provided around the butterfly valve for permitting the flow of a small amount of fluid when the same is in closed position.

Preferably, and as shown, the housing I is cylindrical and is formed at one end with a flange 2 for attachment thereof to the intake manifold, not shown, of an internal combustion engine. The end 3 of the housing, remote from the flange 2, is closed except for a central opening 4 through which projects a fuel chamber, or nozzle, 5, formed intermediate its ends with a flange 5 for attachment, with the end 3 by means of screws I. It

will be noted that the chamber 5 is closed at its upper end and is in communication with the housing only through small apertures, hereafter to be described.

The chamber, or nozzle, 5, is provided with a central portion 8 adapted to act as a fuel inlet chamber and connecting with a source of supply through a pipe 9. At the lower end of the nozzle, and projecting through the inlet chamber 8, is mounted a regulating screw lo having at its upper end a'tapered portion adapted 'toseat in an opening 12 in the top portion, or nozzle portion, 13. Preferably, this top portion i3 is domeshaped.

Disposed in the flange 6 are a series of apertures i l, of relatively small size and adapted to allow the admission under high velocity of air into the housing i under the vacuum caused by the engine. Disposed at the lower end of the top portion l3 of the fuel nozzle are a series of apertures 55 corresponding in number and position to the air apertures l4, and being located in closeproximity and at right angles thereto. By'such ar'rangementair passing in through the apertures M will create an evacuatedcondition in the'chamber 53', which 'will thereuponreceive fuel from the central portion 3 through theopening l2 from the source offuel supply.

Fuel from the chamber it will pass out throughthe apertures it to meet theair rushing in through the apertures M' at right angles, and will be, thereby, broken up and thoroughly atomized.

The size of fuel and air apertures will be determined to some extent by the displacement of the engine by which my device is used, it being intended that the atoniizing mechanism described serves Without adjustment to supply an efficient fuel charge to an engine under all con ditions of speed and load. As the engine speed varies the vacuum which renders my device operative will change and cause largeror' smaller quantities of fuel and air to be supplied to the housing, or main 'chamber, lfof the carburetor. It will be appreciated that the. quantity'of air supplied through the apertures I4 is not enough to form a combustible fuel charge with the fuel supplied through the apertures t5, and that it is contemplated that the sole purpose in ad mitting air at such points is to provide means which will draw fuel 'to' the carburetor from a suitable source and shatter such fuel into small particles in preparation for admixture thereof with suilicient air to constitute a highly oombustible fuel charge. The housing, or main mixing chamber, is provided at one side with an air intake Hi adjacent the end 3 through which air is admitted in quantity 'suflicis'nt to four a combustible charge with the fuel. As: heretofore pointed out, the butterfly valve Ii controls passage of fluid from the housing i to an engine with which it is connected. Said valve centraliy located, journalled on a shaft H and-coin trolled by lever E8. The air inlet it is controlled by a similar butterfly valve i9, journalcd therein on a shaft 2%] and movable simultaneously with the valve H by means of connecting and actuatable by means of lever l8. Since butterfly valve ll will determine. the quantity of fluid passing to an engine, and hence determine the quantity of air which, under the evacuated condition produced by the engine, can be drawn in through the air intake 56, the valve if] controlling the air intake Iii is preferably ad justed soas to open and close simultaneously with the valve ll. ,It may be, however, that to insure the propenproportion of air necessary To render this automatic fuel cut-off inopera to form a highly'combustible fuel charge with the fuel supplied from the fuel chamber I3 through openings I5, that the valve I9 be at all times slightly less open than the valve I I. In this Connection it will be recalled that a certain amount of air passes into the mixing chamber I through the fixed air openings I4, which would decrease the quantity required to be supplied through the main air inlet I6. Any desired relation in position between the valves I I and I9 may be attained by adjusting either the connecting arms, 2i and 22, or by adjusting the valves with respect thereto.

With the arrangementof parts just described, it is contemplated that'when the engine to which the device is attached is running at idling speed, the butterfly valves II and I9 will be in substantially closed positions. To supply a proper fuel mixture under such conditions, a by-pass 23 is located at one side of the housing, or main mixing chamber, I, having a passage-way located therein communicating at 24 with the housing above, and at 25 with the housing below the valve II- when the same is in closed position. Since under such conditions the valve I9, controlling the main air supply, will also be closed, and since the air passing in through the fixed openings I4 is insufiicient'to form a combustible mixture with the fuel, an auxiliary air inlet 26 is provided in theby-pass. A longitudinally extending partition-21 is provided in the by-pass between the fuel and air passages, and two adjustable screws, 28 and 29, are provided to insure the proper mixture of air and fuel suitable for the engine when operating at idling speed.

The arrangement just described is of considerable value in insuring proper operation of the engine, since it has been found that the proportions of air and fuel best for the engine at running speeds are not entirely satisfactory for the engine when the same is idling,

As heretofore pointed out, the fuel chamber, or nozzle, 8, is connected with a suitable source of supply through a pipe 9, and by reason of the particular arrangement of parts heretofore described, fuel will be constantly supplied to the engine as long as the same is in operation. In so far as successful operation of the present oarburetor is concerned, it is immaterial where the same be positioned relative to the engine. It may be equally well employed for down-draft or up-draft carburetion. To prevent gravitational flow of fuel from the source of supply when on a steep down grade and to prevent fuel from being supplied to the engine when an automobile is coasting against the engine, which ordinarily would cause fuel to be supplied to the carburetor, it is proposed to employ an automatic valve which will cutoff the fuel supply to the carburetor under such conditions. To this end an auxiliary fuel saving device is provided in the fuel line 9, or at the junction between the fuel line and the fuel nozzle 8. As best shown in Fig. 4, such device comprises a casing 30, closed at one end by means of a cap 3|, and provided with a passage 32 intersecting thefuel line 9. A ball 33 rides in the passage 32. The device is so positioned with respect to an automobile that as the same tilts forwardon a hill, the ball under the action of gravity moves to restrict the flow of fuel through the pipe 9, the recessed seat 34 being provided at the end of the casing 38, associated with the pipe. As the automobile assumes its normal horizontal position, the ball will roll back toward the cap end of the casing to open the pipe.

tive, or to restrict its operation in case itis desired to maintain the engine running on downgrades, a plunger, 3'5, extending into the passage '32 through the ball seat 39, is provided, the

same constituting a stop for the ball as the same moves to close the pipe 9. The plunger 35 may be conveniently controlled through a lever 36,

extension member 37 and rod 38 from the dash of the automobile by means of a nob 39, as best shown in Figure 6.

As heretofore generally stated, the carbureting device shown in Figures 1 through 5 is of such" character as will enable the same to supply itself with fuel from any suitable source without the necessity of using a fuel pump or vacuum tank. Such is the case by reason of the fact that fuel from a source is constantly supplied to the nozzle 8 by reason of the fact that air passing into the mixing chamber, I, through openings I4 produces a partially evacuated condition in the top fuel chamber I3 of the nozzle from which the same passes outwardly through openings I5 to be vaporized and admixed with the incoming air from the openings I4, and thereafter to be further mixed with the air passing in through the main air inlet I 6. The ordinary float chamber, or reservoir, usually present in carburetors under varying conditions of speed and load. Successful operation is not dependent upon the action of gravity, but on the other hand, utilizes the pressure of air operating at the fuel source to force fuel into the' fuel chamber of the carburetor, and thence into the mixing chamber by reason of the evacuated condition produced by the engine therein. For this reason it is by no means necessary that the carburetor be located at, or below, the level of the source of fuel.

In Fig. 6 I have illustrated a practical embodiment of my invention wherein the carburetor, I, is shown applied to the intake manifold 40 of the engine in an automobile, the same being directly connected to receive fuel from the fuel tank M, located at the rear of the car, through pipe 9,. The various operative parts of my carburetor having heretofore been described and being illustrated in Figs. 1 through 5, are shown more or less diagrammatical in Fig. 6. With the explanation above given it will be understood that the carburetor takes fuel through the line 9 from the fuel tank 4i, atomizes and admixes the same with air to form a highly combustible fuel charge, which is supplied to the 7 engine through the intake manifold 49 as re quired. No special provision is made in the fuel tank in order to assure the proper feed to the carburetor, it being contemplated that such tank be of the type ordinarily used wherein a small hole is provided in the cap, or at some other convenient point in the tank, so that the fuel therein will be subject to atmospheric pressure.

From theforegoing description it is apparent that I have provided a novel and efficient device for the atomization of fuel and automatic means for securing economy in the use thereof.

It is to be particularly emphasized that where as the modern trend in carburetors is towards highly complicated structures having numerous working parts, the carburetor of the present invention is simple to the extreme, cheap to manu facture, and having relatively few parts. Essentially it comprises only a small chamber at tachable to the intake manifold of an internal combustion engine, fixed fuel nozzle connecting with a source of sup-ply, and a fixed air intake adjacent the fuel nozzle and formed relative thereto so as to insure thorough vaporization of the fuel and admixture thereof with the air. The efficiency of my device over other carburetors in effecting fuel economies and preventing c-arbonization of the engine cylinders by reason of its superior fuel vaporizing and charge forming ability has been demonstrated by actual tests.

Although I have illustrated only one form which may be employed in the practice of my invention, it will be apparent to those skilled in the art that the invention is not so limited, but that the embodiment shown is capable of various minor modifications, and that other embodiments may be employed without departing from the spirit of the invention or from the scope of the appended claims,

I claim:

1. In a fuel supply system for an internal combustion engine, a carburetor including a mixing chamber, a fuel dome projecting into the mixing chamber, a source of fuel connecting directly with said fuel dome, the dome having apertures in its side wall leading from the interior thereof into the mixing chamber, and high velocity air inlet communicating directly with the atmosphere in the wall of the mixing chamber surrounding the dome and opposite the fuel apertures adapted to cause the fuel to be supplied to the mixing cham-- ber in highly atomized condition.

2 In a fuel supply system for an internal combustion engine a main fuel supply tank, a carburetor including a mixing chamber, a fuel dome projecting into the mixing chamber through the chamber wall and connecting directly to said fuel supply tank, said dome having apertures in its side wall connecting the interior thereof with the mixing chamber, and minute apertures in said mixing chamber wall positioned externally of and about said dome and communicating freely with the atmosphere to create a high velocity flow of air to atomize and facilitate the supply of fuel to the mixing chamber, and an additional main air inlet to mix air with the atomized fuel and carry it to the point of consumption.

3. A carburetor including a main chamber havihg an opening in the wall thereof, a fuel atomizing element projecting into said main chamber through said opening, the same being connected to a source of fuel and comprising a cone-shaped hollow dome member having apertures about its base, a restricted inlet in said main chamber in free communication with the atmosphere and said fuel atomizing element and disposed in opposing relation to the fuel apertures through which restricted inlet air enters at a high velocity and maintains the interior of the atomizing element in a partially evacuated condition and feeds said fuel to the chamber.

4. A carburetor including a main chamber having an opening in a wall thereof, a fuel atomizing element projecting into said main chamber through said opening, the same being connected to a source of fuel and comprising a dome member having apertures about its base, a plate adjacent the base of said dome and forming part of the wall of said main chamber, said plate having apertures adjacent and at right angles to the apertures of said dome member, through which air enters at a high velocity and maintains the interior of the atomizing element in a partially evacuated condition and feeds said fuel to the chamber.

5. In a carburetor for an internal combustion engine, a mixing chamber having a port for the admission of air and connecting to the intake side of the internal combustion engine at one end, spaced control valves operating in unison positioned in the chamber between the air port and said end, a hollow fuel dome projecting into the mixing chamber intermediate said valves through the chamber wall, a source of fuel supply con? necting with said fuel dome, the dome having apertures in its side wall leading from the interior thereof into the-mixing chamber, and an auxiliary high velocity air inlet in said wall of the mixing chamber surrounding the dome adapted to cause the fuel to be supplied to the mixing chamber in highly atomized condition there to be admixed with air entering through the main air port. Y

6. In a carburetor comprising a mixing chamber having a main airport and formed for attachment to the intake manifold of an internal combustion engine at one end, control valves oper-. ated in unison spaced within said chamber between the air port and said end, and an opening in the chamber intermediate said valves, 2. fuel atomizing element extending into said-mixing chamber through said opening, the, same com-. prising an apertured fuel head and an apertured flange adjacent the base of said head and providing an auxiliary airintaka the fuel and air apertures being disposed in proximity and extending cross-wise of each'other so that air entering the mixing chamber through the apertures will cause fuel to be drawn from the head into. the mixing chamber. Y

7. In a carburetor, a mixing chamber having a main air port and formed for attachment at its discharge end to the intake manifold of an in: ternal combustion engine, spaced control valves operating in unison positioned in the chamber between the air port and the discharge end, a fuel nozzle projecting through the chamber wall and into the mixing chamber intermediate said valves and connecting with a source of supply, an auxiliary air inlet to the mixing chamber in the chamber wall and communicating directly with the atmosphere surrounding the fuel nozzle for drawing fuel into the chamber, and a by-pass in the wall of the mixing chamber around the valve controlling the discharge therefrom operative when said valve is closed to conduct the fuelair mixture supplied by the fuel nozzle and auxiliary air inlet from the chamber to the discharge.

8. In a carburetor for an internal combustion engine connected to a fuel supply tank,- a chamber having a port for the admission of air and connecting to the intake side of the internal combustion engine at one end, spaced control valves operated in unison positioned in the chamber, the wall of the chamber at a' point intermediate said valves being provided with an opening, a fuel atomizing device extending through said. wall opening and into the chamber, the same carrying a fuel dome which extends into said chamber, said dome having a plurality of fuel apertures at its base opening into the chamber, the-wall of the chamber being provided with air apertures extending adjacent and at right angles to the fuel apertures for the purpose of creating apartially evacuated condition in said dome, and for rawing fuel from the supply tank, a.' manually controlled needle valve controlling the admission of fuel to the fuel dome, and a gravity actuated valve associated with said atomizer to control the flow of fuel under certain other conditions.

9. In a carburetor for an internal combustion engine connected to a fuel supply tank, a chamber having a port for the admission of air and connecting to the intake side of the internal combustion engine at one end, spaced control valves operated in unison positioned in the chamber, the wall of the chamber at a point intermediate said valves being provided with an opening, a fuel atomizing device extending through said wall opening and into the chamber, the same carrying a fuel dome which extends into said chamber, said chamber having'a plurality of fuel apertures at its base opening into the chamber, the wall of the chamber being provided with an air aperture extending adjacent and at right angles to the fuel apertures for the purpose of creating a partially evacuated condition in said dome, and for drawing fuel from the supply tank, a manually controlled needle valve controlling the admission of fuel to the fuel dome, a gravity actuated valve associated with said atomizer to control the flow of fuel under certain other conditions, and a by-pass conduit adjacent the inner control valve to be utilized when said valve is closed.

10. A carburetor including a casing providing a mixing chamber, fuel supply means project ing into the chamber through the casing wall and having a fuel outlet comprising a series of side apertures which discharge directly into the chamber in the immediate vicinity of the chamber wall, high velocity air inlet means in said chamber wall in free communication with the atmosphere and opening directly into the chamber, said air inlet means surrounding the fuel supply means and being located below the level of, but in proximity to, the fuel apertures so that fuel will be drawn into the chamber in the path of the inrushing air.

11. Acarburetor including a casing providing a mixing chamber, fuel supply means projecting into the chamber through the casing wall, a fuel outlet comprising a series of side apertures in said supply means located in close proximity to the chamber wall and discharging directly into the chamber, and restricted air apertures in said chamber wall opening directly into the chamber and at their outer ends being in free communicabetween the air port and the discharge end, a

fuel nozzle projecting into the mixing chamber intermediate said valves and connecting with a source of supply, an auxiliary air inlet to the mixing chamber in free communication with the atmosphere the same comprising apertures in the side walls of said chamber and surrounding the fuel nozzle for drawing fuel into the chamber, said auxiliary air inlet communicating directly with the atmosphere and being operable to supply air when the control valves are closed, a by-pass in the wall of the mixing chamber around the valve controlling the discharge therefrom operative when said valve is closed to conduct the fuel-air mixture from the fuel nozzle and auxiliary air inlet from the chamber to the discharge,and a small adjustable supplemental air intake communicating directly with-theby-pass.

13. In a carburetor for an internal combustion engine connected to a fuel supply tank, a chamber having a port for the admission of air and connecting to the intake .side of the internal combustion engine at one end, spaced control valves operated in unisonipositioned in the chamber, an opening in the chamber Wall intermediate said valves, a fuel atomizing device extending through said opening and into the chamber, the same carrying a fuel dome which extends into said chamber, said member having a plurality of fuel apertures opening into the chamber at its base in close proximity to the opening in the chamber wall, air apertures in the wall of the chamber communicating freely with the atmosphere and-at right angles to the fuel apertures for the purpose of creating a partially evacuated condition in said dome, and for drawing fuel from the supply tank, and a manually controlled needle valve controlling the admission of fuel to the fuel dome.

FREMONT STOKES. 

